This game is entirely in the spirit of Half-Life, with its lot of good ideas. The ambience and the immersion are good, the design is beautiful, the level design very well worked.
I had a trigger bug at the end of zoology3 and I had to load zoology4, but that did not taint my game pleasure.
Thanks to the author and to the converter.

Well, i don't know how you managed to get to the next maps without console. The first map just doesn't start, you are stuck in the bedrooms and the security guard doesn't open anything and nothing happens. When you reach the part where the scientist explodes http://scmapdb.wdfiles.com/local--files/map:uss-darkstar-co-op/zoology3__09-04-09_00-16-32.jpg
it actually never explodes. The scientist thats supposed to do something again just gets stuck walking forward and backwards forever.

The issue is with the monster_scientist's hull size. Since the scripted_sequence is too close to the table, it's hull keeps bumping against the table, making the sci walk back and forth. I got that fixed and i'm currently re-converting this to add the missing sounds, dialogue, and some tweaks for coop use.

Update: Just about done with the (re)conversion after a small hiatus. I have two more maps to ripent/fix, stage another map since Sven Coop doesn't use landmarks to enter a "previous map" to complete part of the story line, then play test with other players. Then it should be done after that :D